Preheat oven to 350 degrees. Grease a 9×13 cake pan. In a large mixing bowl combine melted butter and sugar. Stir in 4 eggs, vanilla, and pumpkin puree. In a separate bowl whisk together dry ingredients. Add dry ingredients to wet ingredients and stir just until all combined. DO NOT over mix. Pour into prepared cake pan and bake for about 40 minutes, or until a toothpick comes out clean. Cool and frost with Simple Spiced Buttercream Frosting. If you like more frosting double the recipe.
Place all ingredients in an electric mixer, like a Kitchen Aid. With the paddle attachment beat on medium speed until well combined and fluffy. If dry add more heavy cream 1 tsp at a time.
Recipe makes 24 servings. Calories per serving 202; Fat per serving: 11g; Carbs per serving: 26g; Protein per serving: 2g.